The present invention relates generally to valve actuator subassemblies, such as those for use in the valve gear of internal combustion engines. More particularly, the present invention relates to retainer clips for holding together elements of a subassembly, such as a finger follower and a hydraulic lash adjuster plunger or pivot. Most particularly, the present invention relates to clips that provide bias loading of the finger followers against associated valve stems during engine assembly.
When assembling internal combustion piston engines of the overhead camshaft type subassemblies including a pivot or hydraulic lash adjuster (HLA) having a cylindrical plunger and a finger follower that is rockable or pivotable about the pivot in engine operation may be provided. The subassembly may include a retainer clip for holding the finger follower in assembly with the lash adjuster or pivot in order to simplify installation of the subassembly into an engine. In such subassemblies, it has been common to provide a groove around the lash adjuster plunger to receive edges of an opening in the retainer clip applied to maintain the finger follower and lash adjuster in assembly. Other subassemblies may include a retainer clip as described in U.S. Pat. No. 6,047,675, which is incorporated herein by reference. Such a clip eliminates the need for the aforementioned groove around the lash adjuster plunger and serves to hold the HLA at a fixed angle to the finger follower to thereby facilitate installation of the subassembly to an engine. However, the clip does not bias the opposite end of the follower against the associated valve stem, and therefore does not encourage the maintenance of proper alignment and contact of the follower to the stem before the camshaft is installed in contact with the follower.
Therefore, what is needed in the art is a retainer clip that simplifies installation of the subassembly in an engine.
Furthermore, what is needed in the art is a retainer clip that maintains the HLA at an angle to the finger follower to thereby ease installation of the assembly to an engine.
Moreover, what is needed in the art is a retainer clip that keeps the finger follower in proper alignment and position with the valve stem until the camshaft is secured to the engine.
The present invention provides an improved retainer clip concept for use in valve actuator subassemblies. The retainer clip has generally a U-shaped body with legs that clip over the end of a wall in the body of a finger follower. A first leg includes a gripping recess that engages diametrically opposite sides of a cylindrical member, such as the plunger of a HLA, as in the prior art. A second leg of the clip includes a guide recess that engages a portion on a first side of the wall at a point offset from the axial centerline of the HLA and closer to the point at which the finger follower contacts the valve stem.
The gripping recess includes opposed resilient edges that frictionally engage the cylindrical surface of, for example, the HLA plunger and hold it in assembly with the finger follower. Preferably, the resilient edges engage the cylindrical surface of the plunger at points nearly aligned on an axis intersecting with and normal to the axial center line of the cylindrical member. The frictional engagement of the resilient edges on the cylindrical surface is adequate to not only retain the parts together, but also to position the HLA at an angle to the finger follower that allows easy installation of the subassembly in an engine.
The guide recess includes a clip edge adapted to engage a first side of the wall whereby substantially only the clip edge of the guide recess contacts the first side of the wall at a point inward from the axial center line of the cylindrical member thereby imposing a downward force on an associated valve stem after the subassembly is installed in said valve train. The moment produced about the pivot point on the HLA keeps the follower in proper alignment and position with said valve stem until the camshaft is secured to the engine.
In a preferred embodiment, the retainer clip is formed as a unitary member from a single piece of spring material. However, an alternative sheet metal embodiment is also disclosed.